Comparison of felodipine and enalapril monotherapy in essential hypertension

This study compared the efficacy and tolerability of monotherapy with felodipine and enalapril in patients with essential hypertension using a double-blind randomised crossover design. Thirty-five subjects (22 male, 13 female--ages: median 48 years, range 31-69 years) entered the randomised phases of the study and 32 subjects completed the study. Following a 4-week run-in placebo phase, the treatments were felodipine ("Plendil ER") 5-20 mg and enalapril 5-20 mg orally once daily for 8 weeks, each with matching placebos. Dose titration was at 2 and/or 4 weeks in each phase. Number of subjects with each different end-of-phase dose were for felodipine: 5 mg--8, 10 mg--11, 20 mg--13 and enalapril: 5 mg--6, 10 mg--9, 20 mg--17. Predose supine blood pressure (mean +/- SEM) was reduced in both active treatment phases compared with the run-in phase (159 + 2/101 +/- 1), but there was no significant difference in blood pressure between the active phases: felodipine 143 +/- 2/90 +/- 1 and enalapril 146 +/- 2/92 +/- 1. The most common adverse effects were for felodipine: headache, flushing, ankle swelling; and for enalapril: cough. Felodipine and enalapril as once daily monotherapy are thus of similar antihypertensive efficacy but with predictably different adverse effect profiles.